From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Emelyanov Subject: Re: [rfc v2 0/7] procfs fdinfo extension v2 Date: Thu, 24 May 2012 23:48:15 +0400 Message-ID: <4FBE907F.8040701@parallels.com> References: <20120523102541.382837149@openvz.org> <20120524180121.GK798@count0.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , Andrew Morton , James Bottomley , "ebiederm@xmission.com" , "tj@kernel.org" , "skinsbursky@openvz.org" To: Matt Helsley , Cyrill Gorcunov Return-path: In-Reply-To: <20120524180121.GK798@count0.beaverton.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On 05/24/2012 10:01 PM, Matt Helsley wrote: > On Wed, May 23, 2012 at 02:25:41PM +0400, Cyrill Gorcunov wrote: > > > >> - finally it would be great to have ability to attach tasks to >> frozen tasks cgroup to thaw them at one moment (the preliminary >> patch I've proposed pretty long ago, but Tejun was modifying cgroups >> code and asked to wait until 3.4 is release, so I didn't check >> the current status of task cgroups at moment, I've it in my todo list) > > This still strikes me as the wrong way to go about freezing for c/r. > You never explained why you had to do it this way. Why can't you inject > the parasite thread, move that thread out of the cgroup-to-be-frozen, > then freeze? Matt, I think that Cyrill copied this from some old wishlist and I didn't update him in time :( The thing is that we seem to have resolved all the issues with freezing/unfreezing the processes we're checkpoiting/restoring, and currently we are OK with the existing ptrace functionality. No more modifications of freeze cgroup are required. Cyrill? > As best I can tell your reply last time only fleshed out the details > of *how* you would like it to work, not *why it needs to* work that way: > > http://lkml.org/lkml/2011/11/30/27 > > Cheers, > -Matt Helsley > > . >